During tissue repair, fibroblast cells chemotax, i.e. migrate in the direction of extracellular chemical gradients, using the numerous biochemical receptors distributed on their surface. This project proposes a new, innovative approach to chemotaxis study by developing a model system and methodology to identify the causality between extracellular ligands imposed onto a fibroblast cell, and the consequent redistribution of intracellular proteins needed to initiate chemotaxis-driving signal cascades. It is our hypothesis that the Mitogen-Activated Protein Kinase (MAP) cascade regulates fibroblast migration by influencing the distribution of the docking protein, Growth Factor Receptor Bound-2 (GRB2), which binds to the surface receptors activated by the known chemoattractant ligand, Platelet-Derived Growth Factor Beta (PDGFB). The current project will test this hypothesis via experiments that utilize our own transparent, single-cell, chemotaxis system nicknamed the microLane, to impose one-dimensional concentration gradients of PDGFB across bovine ligament fibroblast cells. GRB2 molecules of the fibroblasts tested within our system will be labeled and mapped using the fluorescent signatures of nanocrystal Bioconjugates (Q-Dots) bound to GRB2 antibodies, apriori. Quantitative results describing GRB2 redistribution as a function of imposed PDGFB gradients will develop a new and unprecedented method to manipulate fibroblast chemotaxis during wound healing. The results will impact Human health via clinical development of therapeutic technologies in avascular tissue repair, as well as research development of collagen scaffolds and biomaterials needed to advance wound healing. [unreadable] [unreadable]